Allocation of sequential image copy data sets

If you specify the CHANGELIMIT option in the COPY utility control statement, COPY uses real-time statistics to determine when the criteria for CHANGELIMIT is met. If the CHANGELIMIT criteria is not met, COPY avoids allocating the image copy data set.

If you specify the FULL NO option in the COPY utility control statement, COPY uses real-time statistics to determine if a table space has changed pages since the last copy. If the table space has no changed pages, COPY avoids allocating the incremental copy data set.

If the real-time statistics are not valid, the object's space map pages are used to determine whether the CHANGELIMIT criteria is met or, for FULL NO, whether the table space has changed pages. Additionally, if real-time statistics are not used to determine whether the table space has changed pages, the image copy data set is always allocated.